Understanding the Correlations Between Structure, Electronic Properties and Oxygen Vacancy Migration in Samarium Nickelates

Ever growing advances in artificial intelligence for wide variety of applications ranging from driverless automobiles, unmanned aerial vehicles to healthcare, poses new challenges in developing strong, fast, and powerful data storage and computer processors. Strongly correlated electron materials like samarium nickelates with property of resistive switching can be potential candidate for brain like computing. The metal to insulation (MIT) or insulator to metal (IMT) transition in SmNiO₃can be triggered by doping electrons in the d-orbital of Ni. In the current study, we have demonstrated that creating oxygen vacancies (OV) in well-defined order (square planar, pyramidal, tetrahedron) triggers the MIT or IMT transition based on its magnetic ordering (A-AFM, E-AFM, FM, G-AFM, S-AFM, T-AFM) in ground state. The structural changes caused due to OV’s in SmNiO_3-δchanges the electronic properties of oxygen deficit samarium nickelates. We used climbing image nudge elastic band (CI-NEB) implemented in density functional theory (DFT) code to find the activation energies of OV migration with two different pathways, one in ab plane and other along c-axis and activation barriers are 1.15 eV and 0.95 eV respectively. We also studied the effect of different shapes and different concentration of OVs around the OV migration pathway. It is found that in each magnetic ordering, the barrier increases with increase in the shapes (pyramidal, square planar). It is also found that the S-AFM has the least and T-AFM has the highest activation energies, 1.25eV and 1.5 eV respectively. This study will further help us in understanding energy efficient way of triggering the MIT or IMT driven by OV transport in SmNiO_3-_d for designing the next generation electronics